carlson



No. 6l5,475. Patented Dec. 6, |898.

C. CARLSON.

STEAM FEED DEVICE FCR LCG'CARRIAGES.

(Application led Apr. 11, 1898A (No Ilodel.)

Patented Dec. 6, |898.

c. cAnLsoN. STEAM FEED DEVICE FOR LOG CARFHAGES.

(Application led Apr. 11, 1898.)

4 Sheets-Sheet 2.

(No Mod'el.)

Zzfnesses.

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C. CARLSON. STEAM FEED DEVICE FOB LUG CARBIAGES.

(Application tiled Apx". 11, 1898.) (N0 Model.)

Patented Dec. 6, |898.

4 Sheets--Sheet 3.

me mams Pz'raRs co, maremma, vwsmmsfcmw4 n c Patnted Dec..6, |898. C. CARLSON.

STEAM FEED DEVICE FUR LUG CARRIAGES.

(Application led Apr. 11, 1898.)

4 Sheets-Sheet 4.

(No Model.)

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UNITED STATES PATENT OFFICE.

CARL CARLSON, OF MINNEAPOLIS, MINNESOTA, ASSIGNOR OF 'I`\VOTHIRDS TO CIIARL'ES J. IIEDVALL AND CORNELIUS B. SIIOVE, OF SAME PLACE.

STEAM-FEED DEVICE FOR LOG-CARRIAGES.

SPECIFICATION forrnngpart of Letters Patent No. 615,475, dated December 6, 1898.

Application filed April ll, 1898. Serial No. 677.117. (No model.)

To all wiz/0711, t may concern:

Be it known that I, CARL CARLSON, a citizen of the United States, residing at Minneapolis, in the county of I-Iennepin and State of Minnesota, have invented certain new and useful Improvements in Safety Steam-Feed Devices for Log-Carriages; and I do hereby declare the following tobe afull, clear, and exact description ofthe invention, such as will enable others skilled in the art to which it appertains to make and use the same.

My invention relates to steam-feed devices for sawmill log-carriages,and has for its object to provide a simple and efficient device for automatically limiting the extreme movements of the carriage and piston of the motor which drives the same, thereby preventing the carriage from running away and the piston from being run against the cylinderheads.

To the ends above indicated my invention consists of the novel devices and combinations of devices hereinafter described, and delined in the claims.

The invention is illustrated in the accompanyin g drawings, wherein like characters indicate like parts throughout the several views.

Figure 1 is a view, partly in side elevation and partly in longitudinal vertical section, showing a log-carriage and its coperating steam-feed or feed-motor with my improved safety appliance or valve-reversing device applied thereto. Fig. 2 is a horizontal section taken approximately on the lineon2 of Fig. 1. Fig. 3 is a transverse vertical section taken through a portion of the mechanism on the line 003003 of Fig. 2. Figs. 4,556, and 7 are detail views, partly in side elevation and partly in longitudinal vertical section,some parts being broken away, showing portions of the motor and my attachment or safety device, but illustrating different positions which the parts take. Figs. S and 9 are detail views, respectively in side and end elevation, illustrating a modified connection between the trip-lever and the trip-rod. Fig. 10 is a horizontal section corresponding to'Fig; 2, but illustrating a slightly-modified construction. Fig. 1l is a longitudinal vertical section taken approximately on the irregular line w11 fc of Fig. 10, a-nd Fig. 12 is a transverse vertical section taken approximately on line x12 0312 of Fig. 10.

'1 indicates the floor or platform of a sawmill.

2, 8, and 4 indicate the sectioned cylinder, and 5 6 indicate the4 piston of the long feedmotor or carriage-feed device. This cylinder is, as is usual, rigidly secured to the Iioor or platform l. f

7 indicatesthe log-car1iage,wl1ich runs over a suitable track in the ordinary manner and is, connected to the outer end of the pistonrod 5 by means of a depending bracket S. The opposite ends of the cylinder are connected to a valve-casting 9 through pipes 10 and terminal ports ll. This valve casting or seat 9 is provided with a cylindrical valveseat 12, into the upper portions of which ports 13 and 14 open and in the lower portion of 7o which the opposite extremities of a discharge or exhaust passage 15 likewise open. The ports 13 constitute extensions of the pipe-sections 10. A live-steam-supply pipe 16 opens into the port 14, and an exhaust-pipe 17 opens 75 from the central portion of the exhaust-passage 15. A double-headed cylindrical slidevalve 1S is mounted in the seat 12, Vwith its stem 19 working through a stuiiing-box 20. This valve-stem 19 is extended to a consid- 8o erable distance, and its free end is connected to the lower end of a hand-lever 21, mounted on a fixed pivot 22 and operated in the ordinary manner to shift said valve 18 and through the cooperating ports in the valve seat or cast- 8 5 ing 9 to alternately open the opposite ends of the cylinder to live steam and to exhaust.

Each pipe-section 10 is provided with a valve seat or casting a, through the passage of which the steam or other motive fluid 9o passes. The passages through the valve-castings a are normally open, but are adapted to be closed by sliding gate or cut-off valves a.

o.2 indicates bracket projections from the valve-castings o., provided in their upper ends with segmental slots a3.

0L4 indicates short levers provided with pins d5, that work as fulcrums in the cooperating slots d3. The outer ends of these levers d4 are connected to the stems of the coperatroo the lower end of which is connected to the cooperating extension a9 of the lever a4, which is located at that end of the machine by means of the chain or flexible connection b2. In the normal position of the rod b the connection b2 has considerable slack, as shown in Fig. 4.

Coperating with each trip-rod b is a long trip-lever f, pivoted at j". At its upper free end the levers f are provided with sheaves f2 and with fingers or portions f3, that normally engage the hubs of the coperating brackets b under the yielding tension of a weight f4 on the lower end of a chain or flexible connection f5, which runs over the sheave f2 and is attached to said bracket Z9. The two levers f are connected by a long rod f6, and the outward movements of the same are limited by fixed stops f7. The levers f and parts movable therewith are yieldingly held in normal positions, as shown, from the tension of a weightfs, secured to the lower end of a chain or flexible connection fg, having branches flo, that run over guide-sheaves f11 and are atattached to the rod f6.

The valve stem or rod 19 of the reversingvalve 18 is provided with a pair of stop-collars fn, that are spaced apart some little distance. The rod f6 is provided witha pivoted trip-arm f 13, the intermediate portion of which normally works between and acts upon the stops f12 and the free end of which projects beyond said stops. g indicates a releasing-lever which is pivoted at g to the frame or iloor structure. One end of this lever gis connected to the depending stem of a foot-piece g2, which projects above the iioor, and the other end of said lever is provided with a laterally-extended portion g3, which underlies the free end of the trip-arm fw in all of its possible positions.

Operationz. The operation of the mechanism above described is as follows: When the foot-piece gzis stepped upon, the trip-arm f will be thrown into an inoperative position, and in this case the reversing-valve 18 may be moved by means of the hand-lever 21 and the feed-motor controlled at will and in the ordinary manner. However, when the said foot-piece is left in its normal position the trip-arm fls will coperate with the stop-collars f 12 on the valve-stem 19 and the operation of the valve 18 will be controlled automatically. For example, suppose the piston 5 `G and the carriage 7 to be moving toward the right or as indicated by arrows marked on Fig. 1. When the said piston has reached a point, say, within three feet of the cylinderhead, it will come into engagement With the inner end of the trip-rod b and will thereafter carry the same with it toward the right ortoward the right-hand cylinder-head 4. Approximately the first foot of movement of the trip-rod b toward theright will move the triplevers f, trip-rod f6, and trip-arm f 13, and the final portion of this first foot of movement of said trip-rod b will bring the trip-arm f13 into engagement with the right-hand collar f12 on the valve-stem 19, and thus force the reversing-valve 18 from its previous position (shown in Fig. 4) into the position shown in Fig. 5. By tracing the passages through the valvecasting 9 and connections it will now be seen that the live steam or other motive fluid will be directed into the right-hand end of the cylinder and will act in opposition to the movement of they piston and log-carriage and at the same time will cut oi the live steam from the left-hand end of the cylinder, so that the propelling force of the fluid will for `the time beingfbe interrupted or stopped. At

the limit of this first foot of movement of the trip-rod b the right-hand trip-lever f will be thrown into engagement with a iixed stop f7 and its movement will be stopped thereby. The position of the parts at the limit of this first foot of movement is illustrated in Fig. 5, by reference to which it will be noted that the flexible connection b2 has now been pulled taut. Approximately the next foot of movement of the piston and trip-rod will act upon the gate or cut-od valve a" through the connection b2 and lever a4 a9 and will close the said valve, so that the steam or motive fluid will be positively conned in the right-hand end of the cylinder, and will thus be caused to act as a cushion to stop the movement of the piston and 10g-carriage. This action or feature of cutting off or closing the passage to and fromzthe cylinder is very important, for While theboiler-press ure of the steam will be sufcient to materially lessen the speed of the piston and carriage it will in many cases be insufficient to completely stop their movements, and under the compressing action of the piston the steam or fluid in the end of the cylinder will soon be compressed to a higher pressure than the boiler-pressure and would then be forced out of the cylinder were it not for this cut-off or stop valve or some device which in a broad sense would be its equivalent. Attention is called to the fact that in this movement of the lever a4 a in closing the valve a the Weight a7 holds the fulcrumpin 0,5 at the bottom of the segmental slot a3. The position of the parts at the limit of this second foot of movement of the trip-rod b is illustrated in Fig. 6, by reference to which it will benoted that the bracket b has been separated from the free end f3 of the coperating trip-lever f.

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It is possible for the piston and log-carriage to move approximately another foot after the gate or cut-oft valve a is closed against the high tension but cushioned action of the conined steam or fluid; but it will seldom if ever move to the limit of this possible movement. The limit of this possible movement is illustrated in Fig. 7, by reference to which it will be .noted that the fulcrum-pin a5 of the lever a4 has been moved upward in the slot as and the bracket b has been moved on still farther away from the free end f3 of the cooperating trip-lever f.

By the above actions the piston and logcarriage will be brought lto a stop or standstill within the limits of a very short movement,butbysuch an increasingcushion action that no jar will be perceptible. As soon as the piston and carriage are brought'to a standstill the highly-compressed steam or motive Huid in the right end of the cylinder will become effective to give the same their initial return movement toward the left. The first foot ot' return movement under the action of the highly-com pressed air will restore the parts to the positions illustrated in Fig. 6.

'sion of the two features.

limits of its strokes and that a positive cushioned action is also effected. Either one of these features, even if used alone, would give vvery beneiicial results, but for reasons already clearly indicated a much superior action is obtained by the cope1-ationinsuccesywill illustrate the point aswell as many. In

the iirst place it is evident that with the ordinary hand device the utmost care and an eX- treme nicety of calculation by the operator of the hand-lever or device for controlling the reversing-valve is required, for while the piston-head must be run very close to the heads of the cylinder it must never be permitted to strike the same. Hence it so frequently happens that the carriage is run too far, thereby breaking the machinery and often injuring the operator and workmen. Again, if lone of the saws should happen to be broken or thrown o of theirpullevs, as frequentlyhapand the initial portion of the next step of movement will permit the weight al to open the gate or cut-0E valve 0.. 4Live steam will now be again admitted into the `right end of the cylinder and will become eii'ective to drive the piston and log-carriage to the other limit of its stroke or to the lett-hand end of the cylinder.

The stops f12 on the valve-stem 19 are spaced apart far enough so that the valve 18 may be reversed by means of the hand-lever 2l without moving the rod f6 or trip-armf. With the adjustments above assumed said stops j'12 are so related to the trip-arm f13 that the return movements of the trip-levers f and rod or connection f will not move the reversing valve from the position shown in Figs. 5, 6, and 7. The said reversing-valve 18 will be automatically returned to the position shown in Fig. 4 when the piston 5 6 reaches a point at the left-hand end of the cylinder corresponding to the position shown inv Fig. 5.

By adjusting the stop-collars f12 somewhat closer together the return movement of the parts from the position shown in Fig. 5 to the position shown in Fig. 6 will cause the triparm f13 to strike the left-hand collar fu, and thereby give the reversing-valve-18 a halfstep of return movement toward the left and bring it t0 an intermediate position, in which it will close both of the ports 13. This, as is evident, will cut oft live steam from both ends of the cylinder and bring the pistou and carriage to a stop.` In this case it will require the use of the hand-lever to again start the carriage, but the actions indicated Will be accomplished automatically.

It is obvious from the foregoing that the action of the steam or motive fluid on the piston of the carriage-motor will be automatically reversed as said piston approaches the pens,the operator will be compelled to quickly leave his post, thus leaving the carriage uncontrolled to run away and break things up creased strength at points where the pressurewill be greatest under the compression in the cushioned action on the piston.

Figs. 8 and 9 illustrate a modified construction of the connection between the trip-rod b and the trip-1ever f. In this construction the upper end of said lever fis bifurcated at f14 and is provided with a pivotally-connected two-part clamp f 15, the sections of which Work on the trip-rod b and are spring-pressed into frictional engagement therewith by springs f16 on studs f 17. In this .construction the head j"15 slips under frictional engagement on the trip-rod b.

ln Figs. 107 1l, and 12 a modiiied construction of the device for throwing the trip-arm fls out of action is illustrated. In this construction the free end of the releasing-lever g engages the intermediate and under portion ofa vertically-movable plate or bar 7c, the ends of which are provided with bearings that Work upon a pair of depending guide-rods k', the upper ends of which are rigidly secured to a fixed bracket or frame-section 7a2. Heads or enlargements k3 on the lower ends of the guide-rods k' limit the downward movement of the plate or bar k. On the plate or bar k is adj ustably secured a pair of cam-.blocks 7a4, having cam-surfaces 7c, which are inclined in lOO IIO

opposite directions and operate on the triparm fla under reverse movements of the rod f6. With this construction the movement of the rod fitoward the right, as above described in connection with the construction shown in Figs. l to 7, inclusive, the trip-arm f13 will iirst act on the right-hand stop-collar f12 and shift the reversing-valve into the position shown in Figs. 5, 6, 7, and 1l and then will be cammed into an inoperative position, as shown in saidFig. 1l. In this inoperative position. of the trip-arm f13 the reversingvalve may be moved by the use of the handlever 21. The initial return movement of the rod f6 will carry the trip-arm f13 down the incline 705 to the lowest portion of the block,will then throw said arm into contact with the lefthand stop-collar f1?, thereby causing it to move the reversing-valve back into the position indicated in Fig. 4, and immediately after this has been accomplished the cam portion h5 of the left-hand block 7a4 will cam said arm f13 again upward and hold the same in an inoperative position, so that the reversing-valve may be freely operated by its handlever. This cam -trip thus serves .to automatically let in steam to that end of the cylinder toward, which the piston, after having been stopped by the cushion device above described, will tend to rebound under the expansion of the highly-compressed steam or iiuid confined in the cushion end of the cylinder.

From the foregoing description and statements made it is thought to be obvious that my invention is capable of a very Wide range of modification, and hence it will of course be understood that I do not limit myself to the details of construction illustrated in the accompanying drawings.

The expression a cut-oit valve movable to close the exhaust-passage from the cylinder, as used in the claims, is used in a sense broad enough to cover a modification of the specific construction shown, wherein the reversing-valve itself is provided with sufficient lead or lap to perform the function indicated. lVhile a sin gle reversing-valve has been illustrated, it will be understood that any operative modification or substitute construction might be employed.

What I claim, and desire to secure by Letters Patent of the United States, is as follows:

l. The combination with a fluid-pressure feed-motor and carriage driven thereby, of a cut-oft valve movable to close an exhaust passage or opening from the cylinder, and a device operating independent of the feedvalve mechanism of said motor, for closing said shut-off valve to form a cushion in the cylinder of said motor, substantially as described.

2. The combination with a reciprocating fluid-pressure motor, and' carriage driven thereby, of a cut-off valve movable to close the exhaust-passage from the cylinder, and a valve-controller operating automatically to close said valve and cut olf the exhaust,when the said piston closely approaches the limit of its stroke, substantially as described.

3. The combination with a reciprocating fluid -pressure motor and carriage driven thereby, of a cut-off valve in one exhaustpassagefrom the cylinder of said motor, and an automatic valve-controller, actuated by the piston of said motor and operating to close said cut-oit valve, when said piston closely approaches the limit of its stroke, substantially as described.

4. The combination with a straight-line fluid --pressure motor and carriage driven thereby, of a cut-oit valve in one exhaustpassage from the cylinder of said motor, and automatic valve-controlling mechanism, operating, primarily, to reverse the action of the motive fluid on the piston of said motor, and secondarily, to close said cut-off valve and form a closed cushion in said cylinder, substantially as described.

5. The combination with a reciprocating straight-line fluid-pressure motor and carriage driven thereby, of cut-off valves in the exhaust-passages from the opposite ends of the cylinder of said motor, and automatic valve-controlling mechanism actuated by the piston of saidl motor, and operating, primarily, to reverse the action of the motive fluid on said piston, and secondarily, to close said cut-off valves, substantially as described.

6. The combination with a reciprocating straight-line duid-motor and carriage driven thereby, of automatic valve-controlling mechanism, comprising a trip-rod Working through one cylinder-head, and a yielding connection between the same and the reversing valve or valves of said motor,'said parts operating substantially as described.

7. The combination with a reciprocating fluid-pressure feed-motor and carriage driven thereby, of automatic valve-controllin g mechanism, comprising a trip-rod working through one cylinder-head, a trip-lever connected to the reversing valve or valves of said motor, and a weight and flexible connection yieldingly holding said trip-lever for movement with said trip-rod, substantially as described.

8. The combination with a reciprocating fluid pressure motor and carriage driven thereby, of a cut-od valve movable to close one exhaust-passage from the cylinder, comprising the gate-valve a', the bell-crank lever, with shifting fulcrum, the weight normally holding said fulcrum down, the trip-rod working through one cylinder-head, and a con nection between said trip-rod and said bell-crank lever, substantially as described.

9. rllhe combination with a reciprocating Huid pressure motor, and carriage driven thereby, of a cut-O valve in one exhaustpassage from the cylinder of the motor, an automatic valve-controlling mechanism, actuated by the piston or part moved thereby and provided with yieldingly-connected parts, whereby it operates, primarily, to reverse the IOC IIC

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action of the motive iiuid on said piston, and, secondarily, to close said cut-off valve, and then t0 permit further movement of said pis ton Without destroying the set positions of said cut-oft` Valve or the reversing-valve of said motor, substantially as described.

l0. The combination with a reciprocating fluid pressure motor and carriage Y driven thereby,Which motor has a passage that serves both for the admission of live steam and for the exhaust, of a cut-od valve in said passage, and valve-controlling mechanism operating primarily, to reverse the action of the motive fluid on the piston of said motor, and secondarily, to close said cut-od valve, substantially as described. y

ll. The combination with a carriage, of a coperating cylinder and piston, one iixed and the other movable with respect to said carriage, a cut-o valve movable, to close an exhaust-opening from said cylinder, and automatic connections actuated by the piston or part moved thereby, and operating to close said cut-o valve to form a cushion Within said cylinder, substantially as described.

12. The combination With a straight-line motor and carriage driven thereby, of a handoperated device connected to the reversingvalve of said motor, and controlling mechanism operating to reverse said reversi1ig-valve, When the piston closely approaches the limits of its stroke, and a releasing device for rendering said automatic Valve-controlling mechanism inoperative, at will, substantially as described.

13. The combination with a reciprocating iiuid -pressure motor and carriage driven thereby, of automatic valve-controllin g mechanism operating to reverse Athe reversingvalve of said motor, when the piston thereof closely approaches the limits of its stroke, and a releasing device operating automatically to again reverse the reversing-valve and render said valve-controlling mechanism inoperative, under the initial return movement of said piston and carriage, substantially as described.

In testimony whereof atlx my signature in presence of two Witnesses.

CARL CARLSON.

Witnesses:

BEssIE B. NELSON, F. D. MERCHANT. 

